Like Father Like Daughter
by iguessso12
Summary: Yui is their daughter, though not in any technical definition of the term. But when the characteristics she shares with Asuna and Kirito grows unbalanced, mama senses something fishy. A sort of character analysis of the AI, Yui. A little bit of warm fuzzies within. Contains references to the novels, but not necessary for enjoyment. Occurs after anime. Further explanation inside.


**So, here I am again, writing more SAO fanfiction. I don't know what I was thinking, 'cause writing about the main characters just seems like a really bad idea. I tried to keep them as in character as possible, so hold me to that.**

**Anyway, this story is a combination of a rabid plot bunny and my own personal headcanon. Yui is what's called a 'top-down AI' which means she is given computer programming to respond with the most ideal answer in a situation. But on the other hand, she is able to expand and compile said answer-selection system, so – essentially – she learns to develop more detailed reactions.**

**Because Yui's program was saved to Kazuto's NerveGear, and she helped him find Asuna, and because he's the more computer savvy of the pair, it would make sense that Yui spends more time around Kazuto. And as a result, she acts a lot like him.**

**Not to mention, I just think it's downright adorable how Yui is like his personal assistant – as a pixie – in both the show and the novels. And… I got to throw around a bit of lingo from my programming class!**

**Writing it from Asuna's perspective just made the most sense because she knows Kirito/Kazuto so well, she'd be able to see it. So of course, having the lovebirds in the story together resulted in a little bit of romance – not much, but a little. I love those two! OTP and it didn't even take half the story this time. (Yeah, I did make a little allusion to my last fic in this one, but it's no big deal)**

**Whelp! I hope you enjoy! And if you perchance had a thought and a moment to write it down, it would be welcome. Authors note, STOP!**

* * *

Asuna had always found it delightfully coincidental that Yui genuinely looked like a combination of her and Kazuto.

The girl's lengthy hair imitated Asuna's long style but the shade of her locks resembled Kirito's, only a much more pale black. Her round eyes were shaped like Asuna's, and the color was the perfect mixture between autumn-auburn and midnight-black: dark-chocolaty brown. Her delicate face was full and round – like Asuna – but her frame was so skinny it sometimes looked painful – like Kazuto.

Now, most people would object and say Yui looked exactly like Kirito, but that was _not true_. Maybe it took a mother's loving eye to see the similarities; Yui had lots in common with Asuna!

Right?

* * *

Asuna wasn't sure when she first noticed it, maybe around the time she had started looking for those commonalities she shared with her daughter that lay beneath the surface of that little AI girl. But there was definitely, _definitely_ something wrong with this picture. She couldn't quite put her finger on it.

But she would find out.

* * *

The moments when she saw _it_ were so quick, she had to use all her focus to catch it.

Like the one time Recon – Lyfa's boyfriend – got a little too close to Yui, in a locational sense. He had his yellow-green head only millimeters from the pixie's tiny frame, and was attacking her with tactless questions about her programming and intelligence logarithms. It wasn't very polite, but maybe the kid just had a little too much enthusiasm than what was good for him.

Lyfa finally pulled him away, dragging him back by the hood, and scolding him profusely.

But in the split second after the Sylph boy had made his special little obnoxious apology, _it_ had appeared.

A small, bitter smile

* * *

Another instance came not but a week later.

Klein was being difficult… again. Doing what he did best, he had riled half the group up the moment Kirito had left to scout ahead. Without their leader, Klein thought it was his manly duty to protect the rest (who were all women). Needless to say, Liz did not agree. And now the two were in a shouting match loud enough to attract the attention of every monster in the dungeon.

"Klein!" Asuna employed her commanding tone from her old KOB days, "We will all do our fair share of the fighting. You don't need to swoop in and grab everyone's EXP and disguise it as chivalry!"

The redhead stuttered for a moment as Liz stifled her victorious giggles.

"It's not 'cause I'm being selfish, Asuna-san!" he objected, outraged that she would assume the worst, "It's part of my _'bushido _code._'_ Protecting fair maidens is in the job description!"

From the front of the group where she was scanning for enemies, Yui cast an exasperated look back at the katana wielder: "Oh please."

* * *

Then again.

Silica had fallen asleep – on the floor of all places.

It was winter on the 22nd floor of New Aincrad, so the moment Asuna had logged in, she had started up the hearth in anticipation for guests. Kirito, Sinon, and Silica were the first to arrive, offering to help her set up. But when Asuna had run out of jobs for them to do, Kirito had settled into a barstool, content to watch her like the creeper he sometimes was; Sinon said she was going out to shoot something and would be back soon; and Silica had wandered into the living room and fallen victim to a cat-nap.

Now the young girl was curled up like a kitten on the rug in front of the flickering, orange flames. Her tawny ears twitching in her dreams and tail curled lazily around her legs. Pina was tucked under the crook of her arm, cooing a lullaby for her sleeping master.

Asuna brought the tea things out to the end table only to see Yui observing the sleeping Cait Sith.

A familiar, gentle look of affection decorated her daughter's face.

* * *

If she watched closely, she could see it every time they started a new quest.

While Yui didn't do any of the fighting herself, she loved to be in the fray. She would sit on Kirito's shoulder or nestle in his coat pocket as he did his thing; that is, whirl through hoards of monsters like a god of destruction. And even from her support position, Asuna could hear the pixie's exclamations of pure delight:

"Woo-hoo!"

"Go, get 'em papa!"

"One behind you!"

"Klein's on you left, so be careful!"

"HIYA!"

She enjoyed it way too much.

One time, Yui had tried to stay back with Asuna, advising her on the timing for her healing spells or even suggesting some interesting new magic. But it hadn't lasted long.

"I'm going to go help aunty-Lyfa," she said, somewhat hesitantly, as if she was afraid of hurting the Undine healer's feelings.

"Good idea, it looks like she could use some assistance."

Yui disappeared into the mob, her miniature form completely invisible amongst the commotion, but her battle cries rang out loud and clear.

* * *

Again and again, Yui's actions, interests, and expressions would give Asuna a sudden sense of déja-vu.

Her innocent, sleeping face that made her appear years younger.

Her love of spicy food.

Her faraway, thoughtful expression that looked like a mix between extreme focus and zoning out.

Every time, it struck a chord of familiarity within Asuna, but she still couldn't seem to understand _why_? The more she saw _it_, the more _it_ bugged her. She was going to figure this out. The answer was on the tip of her tongue. And not knowing was frustrating her endlessly.

It was six months after her release from ALfheim Online when she figured it out.

* * *

Asuna was bored.

It didn't happen all that regularly, that she genuinely had nothing to do, but today was one of those rare days. Her mom was off on a research trip for her university, her dad was in America, and her brother was at work. She had finished all her homework for the weekend in ALO on Friday. She, of course, had no chores; the maid could take care of that. And to be frank, she had no friends – at least, not nearby.

She flitted through the Yuuki Mansion, fidgeting when her hands found nothing to preoccupy them. After an hour, she couldn't take it anymore.

Asuna sprinted to her room, brown hair streaming out behind her as she threw open the door and dived onto her bed. She reached forward to grab her mobile off the nightstand, barely pausing before hitting a number on her speed-dial. Her fingers drummed on the comforter as the phone rang… and rang and rang. She tried to suppress her disappointment as Liz's voicemail picked up and hung up without leaving a message.

Sinon! Surely, Shino wouldn't have anything going on. She lived alone and didn't have school on the weekend – obviously. But after pressing another button and again listening to the call rollover, she found herself discouraged yet again.

She didn't want to log in to ALO alone. It was boring without her friends (who were all busy, apparently). Klein and Agil would both be at work, and she usually didn't hang out with them alone. If she went anywhere it would probably an aimless and long walk in the cold – not worth it.

She just wanted to talk to someone.

Usually, this is when she would resort to calling Kazuto. But she had texted him earlier and he had said he was starting a project that would probably take him all day. She didn't want to bother him, and he had promised they'd go out tomorrow.

Kazuto. That reminded her…

She closed her contact list, summoning the home screen of her phone. Quickly scrolling through her apps she picked out the custom-made one Kazuto had uploaded for her.

Even though it was her favorite program, she didn't use it much, and usually only when she was at home. It burned through her battery in record times, tending not to last longer than twenty-five minutes. Something about the refresh rate for high quality images; she remembered Kazuto mumbling about the incompetency of modern technology. That was generally when she let him be; sometimes, there was no reclaiming him once he started down that road.

Regardless, she opened the app now. It was one that could connect her directly to Yui in the VR world. Kazuto had designed it specifically for Asuna and it would lock on Yui's signal as long as she was on the ALO server. With it, Yui and Asuna could see each other, converse, and simply enjoy some mother-daughter bonding time IRL. It was invaluable, as Asuna wasn't always available to dive when she wanted to see her daughter.

But Yui wasn't there.

This had been happening more and more often as of late. Asuna would open the app in anticipation to see her daughter's smiling face and sweet call of 'Mama!' only to receive a blank screen.

It should have been impossible. If the pixie was in the server, the program would find her. Kazuto had explained it plain as day. And there would be no reason for Yui to leave ALO.

Yet the display was devoid of Asuna's little spot of sunshine. A small error message scrolled across the bottom of the mobile: 'address not found.'

What?

Maybe Kazuto would know. She hated to interrupt, but the fact remained: she was his girlfriend, and that took precedence over whatever doohickey he was working on today. This was a family emergency.

And… there could also be the reason that she _just wanted someone to talk to!_

Asuna pressed 'one' and 'send' without another moment's hesitation, sighing with gratitude when the receiver clicked on. But it wasn't Kazuto's voice that answered.

"Asuna-san!" Kirigaya Midori's voice clearly rang across the connection, "I'm sorry. I know I'm not who you're looking for, but Kazuto left his mobile downstairs on the kitchen counter this morning, and he hasn't come out of his room since. I thought since it was you calling, you'd appreciate some _intervention_, if you know what I mean."

"Ah, thanks Kirigaya-san." The unexpected development delayed her response to Kazuto's mother's information, "Geez, that boy! That room of his is like a death trap. He won't resurface until someone drags him out will he?"

Midori laughed, an easy-going sound that Asuna couldn't ever remember hearing from her own mother, "No, I guess he won't. But I can definitely sympathize with him. He's just like me; once he gets started on something he can't stop till it's done."

Asuna didn't say anything to that, not sure how to respond to such a confession from an adult. But at the same time, that determination was a quality she admired about Kazuto.

"I could get him for you… maybe. But it might just work better if you come over," Midori's words interrupted Asuna's musings, "I'm headed out to a meeting that will probably last all afternoon. It's Suguha's turn to make lunch – which would have resulted in salad for everyone – so I'm sure both of them would appreciate if you came to visit."

Somehow, with just one phone call, Midori had deduced Asuna's plight. A mother's intuition indeed.

"Right!" Asuna felt her own words sounding dreadfully upbeat and desperate, "Then I better be on my way!"

"Me too." Asuna could hear the smile in Midori's voice. The woman was no doubt laughing internally, but that didn't matter.

"Have a good day, Kirigaya-san."

"You too, Asuna, and good luck!" the phone clicked off, but Asuna barely heard it. She was already in a frenzy, hurrying to prepare for the trip across town.

* * *

The Kirigaya's house in Kawagoe wasn't that big or beautiful, but it held its own among the mess of buildings in the district. The traditional-style, Japanese architecture was outfitted with modern amenities; it was comfortable and functional. The property itself would probably be considered large for a family living in the suburbs of Tokyo; Kazuto had told her it had been passed down through the family. That probably explained the small dojo at the rear of the lot, as Kazuto's grandfather had been an avid kendo artist.

Asuna let herself in through the front gate, stopping on the smooth, wooden doorstep to knock. Within seconds, the light tread of footsteps resounded within the house and the door opened.

Kirigaya Suguha stood there. Wearing a casual sweat suit and a smile, the younger girl invited Asuna in, chattering excitedly:

"Thank goodness! I've been bored all day! Kazuto's being antisocial, and I don't want to do my homework, and _oh my gosh Asuna_ will you spar with me!?"

Asuna put her hand up, trying to stem the tirade of exclamations from Kazuto's overeager, younger sister, "Hold up, Sugu. One thing at a time!" She bent down to slip off her shoes and buy a few seconds.

"I need to talk to Kazuto first, real quick, then I'll have time to… do whatever it was you just suggested."

"Roger!" Suguha was brimming with energy, but she let Asuna past. The auburn haired girl confidently climbed the stairs and turned down the hallway. She made it to the door before being suddenly struck with anxiety: what if he got upset with her for interrupting? Sure they were in love, but that didn't always negate the teenage insecurities that lingered in the back of her mind.

Stuck in quiet indecision, she was able to hear voices emanate from within the room. Strange, if he was working, he wouldn't want any disturbances. And why did it sound like a girl's…

"…Run that one again." Kazuto's smooth tone was as familiar to her as her own.

"Right!" the answering reply sounded small in comparison.

"Adjust the angle to the right by thirty-seven degrees. Zoom. Focus. Alright, stop it there. You getting a clear picture?"

"Yes papa, but you still haven't written the code for automatic light-and-dark adjustment. There's just a slight glare. I can fix it, but I have to open the menu."

"Fine, I'll do that next. Yui, do a check on all that script. You can fix any syntax errors I might have made. When you're done, let me know. Then we'll reconfigure the code to substitute the retrieval address for synthetic nerve functions."

"Right, Papa."

A lull occurred in the conversation, the only sound was the light tapping of a keyboard, but Asuna's thoughts were flying a million miles an hour.

Yui was here, with Kazuto, which was why she hadn't been on in ALO. It was probably the same for all the other times she had tried and failed to contact her daughter.

But something else clicked in her brain. Kazuto would be proud of her technical deduction: Yui was an AI. Every moment she collected bytes of information to add to her response index; if she was with Kazuto, then she was learning things from him.

Suddenly, that _thing_ that had been bothering her for months became painfully obvious.

Yui's expressions.

Every one of them.

Kirito's.

Kazuto's.

His bitter smile, his loving look, his innocent face, his focused eyes.

Every crack she had ever seen in Kazuto's usual poker face had been reflected on Yui's tiny features.

Only his.

This information dropped like an anchor in her stomach. She couldn't believe it. He's been…

"Kirigaya Kazuto!" she yelled, the sound carrying through the house as easily as a leaf on a windy day.

Asuna loudly grabbed the handle, bursting through the door with all her fury personified. She stomped across the darkened room where Kazuto sat before his custom-made, triple monitors. Unintelligible text covered all of them, save the last, where Yui's figure was displayed bending diligently over a digital keyboard in a cozy-looking computer terminal.

The boy in question spun around in his swivel desk chair to face his belligerent girlfriend. His stygian colored eyes widened in recognition and surprise.

"Hey Asuna." His voice was perfectly calm, but Asuna knew Kazuto better than most. She had caught that fleeting look of fear and the way he almost hesitated when he said her name before his straight face fell into place, revealing nothing. "I didn't know you were coming."

"Of course you didn't, because you don't bother to answer you phone. No, your mommy had to do that for you!" She exploded, using everything within reach as verbal ammunition, "But that's beside the point!"

"Then what is the point?"

Oh, the way he feigned innocence really infuriated her, because he was just so damn, irresistibly cute. But she was not giving in, not this time. This was serious business.

"The point is, _YOU'VE BEEN CORRUPTING OUR DAUGHTER!_"

Her accusation was met with silence before…

Kazuto whirled around in his chair, earnestly facing their daughter who was watching the scene in interest, "Is Asuna right? Yui, do you have a bug, a glitch, a virus? Run a quick scan."

A second passed, "No papa, I'm fine." She shook her delicate, little head.

Kazuto's shoulders slumped with relief. He turned back to Asuna with a sigh and a smile, "See, everything's fine."

"You _IDIOT_! That's not what I meant by that. I mean, _you are monopolizing our daughter_."

Now the confusion was clearly written across his face, "What do you mean?"

"You've been keeping Yui to yourself. Now she's just like you!"

Kazuto frowned, "She's been helping me with my research."

"What research?"

"My theory of Augmented Reality. Right now I'm basically reverse engineering the NerveGear and changing the inputs…"

Asuna held up her hand for him to stop.

"She's an irreplaceable helper," He said gently, "And she's been learning things too."

"So now you're just using her?"

"No." he said, but it came out sounding weak.

"I don't mind mama!" Yui spoke up from the desktop monitor, "This is how I spend time with papa!"

She sighed, putting her fingers to her forehead, "You're just as bad as he is, aren't you?"

"What do you mean mama?" Yui tilted her head to the side, a perfect imitation of Kazuto when he was curious about something.

"I can't believe you two." This time her voice was tinged with resignation as she closed her eyes. It was hopeless. After years of being around the Black Swordsman, then Kirigaya Kazuto, she knew that there were some things you couldn't change. It seemed Yui had picked up that trait of stubborn immutability.

She didn't hear him approach, but warm arms wrapped around her body, squeezing her shoulders in a secure hug. Asuna leaned into it, despite her earlier frustration with him. The happiest moments of her life were the ones where he held her; a promise that they would always be together.

This boy – no, he was almost a man – was the love the love of her life. She counted herself lucky that she had found him so early. Because of this they had added years to the time they could spend side by side. Wherever he went, she would follow; and he would never leave her behind.

Maybe the whole reason she had stormed up here, started a 'heated' conversation, and given up so easily was because she just wanted to be with him. Those damn teenage hormones just made her way of getting there a bit irrational. Good thing Kazuto was not so easily deterred.

She reached up, curling her hands around him to rest on his shoulder blades. Closing her eyes tighter, she snuggled deeper into his thin chest.

"Sorry for hogging Yui," His voice was quiet in her ear, but there was an unmistakable chuckle in his tone.

"You're so selfish," she grumbled into his shirt, "You need to learn to share."

Kazuto somehow deciphered the muffled sounds. His arms around her squeezed tighter, almost painfully, but only for a moment. In a low voice he said, "Sometimes, I don't care if I'm selfish. I'm not sharing you and I'm not sharing Yui. Not. With. Anyone."

Asuna smiled, and even though it was hidden, she knew that he knew she was doing so, "I love you. I love you both."

Kazuto made a small noise of agreement, the sound vibrating though his chest where it mingled with his heartbeat. Asuna could stay like this forever, surrounded by his warmth and the sound that confirmed that he was alive. She didn't know how long passed before he released her so he could hold her face with one hand.

"Are you still mad?" His face was serious, but Asuna knew he was teasing her.

"No."

"Good," He glanced at the clock on the wall, onyx eyes flashing with that simple movement, "Because I believe it's getting close to lunch time, and I'm starving. I really hope you plan to stay for Sugu's salads!"

She pushed him away, "You're not being discrete at all. I know you want me to cook."

Abandoning all composure he brought his hands together in supplication, "Please, oh please."

His midnight eyes begging, he looked more like a kicked puppy. Asuna resented how easy it was for him to get her to do things for him, but then again, it went both ways.

"Yui's coming with me!" she announced, brushing past him to link her mobile up to his computer.

"What? NO!" he spun around and grabbed her wrist, "I _need _her!"

"Then I guess you don't_ need _lunch do you?"

"But it's so much easier with her help. I…"

Asuna shot him a sideways glare and any further objections died in his throat. Yui's transfer was complete within seconds.

From the small screen, the little girl consoled Kazuto, "It's okay papa. You're smart. I know you can do it. I'm gonna help mama now."

Kazuto was still as stone as Asuna passed by him and stepped into the hall. He still hadn't moved when she called Suguha to help her with lunch preparations and shut his door. He'd be fine.

In the end, maybe it didn't matter that Yui was more like Kazuto. She was still their daughter. And even though the boy himself was a handful, she could manage a little more of him in her life.

Fin

* * *

**Citations/Proof that Yui learned most of her response patterns from Kirito/Kazuto**

**_The bitter smile:_**** Volume 10, Chapter 2 (Yui explicitly says that she's imitating Kazuto's expression as she talks about her nature as an AI)**

**_"Oh please.":_**** Episode 9 (What Kirito says in exasperation to Klein's antics after the 74****th**** floor boss fight)**

**_The look of affection_****: Episode 15 (I'm referencing Kirito's expression when watching Asuna fall asleep on his shoulder during his nightmare at the beginning of the episode)**

**_Enthusiasm for battle:_**** Episode 12 and 19 (Yui cheers on Kirito when he fights)**

**_Innocent sleeping face_****: Episode 11 (Asuna watches both Kirito and Yui sleep… creeper)**

**_Love of spicy food_****: also Episode 11**

**_Faraway/zoned out expression:_**** Episode 25 (I can really only cite this for Kazuto, not Yui, but this ****_is_**** my own headcanon; there shall be a few stretches of the imagination :)**


End file.
